Four people were killed and thousands forced to flee their homes as floods inundated large parts of the northern Philippines, the government said Sunday.

Heavy monsoon rains lashed the largely agricultural provinces for days, bringing floods that left roads impassable and led about 3,000 people to be evacuated, government civil defence officers said.

At least four people died as a result of the rains, including a six-month old boy who was buried by a landslide in the northern province of Pangasinan, the officers said.

Social welfare and relief agencies are delivering aid to affected areas while the public works department is preparing to repair damaged infrastructure, said President Benigno Aquino's spokesman Herminio Coloma.

Although no storm is forecast to hit, the government weather station warned that "monsoon rains which may trigger flash floods and landslides will be experienced," over large areas of the northern Philippines on Sunday.

The disaster-plagued Philippines is hit by about 20 typhoons and storms each year, many of them deadly.

Earlier this month, Tropical Storm Linfa inundated whole towns in the north, although no fatalities were reported.